Remodeling of Interstrand Crosslink Proximal Replisomes Is Dependent on ATR, FANCM, and FANCD2
Jing Huang,
Jing Zhang,
Marina A. Bellani,
Durga Pokharel,
Julia Gichimu,
Ryan C. James,
Himabindu Gali,
Chen Ling,
Zhijiang Yan,
Dongyi Xu,
Junjie Chen,
Amom Ruhikanta Meetei,
Lei Li,
Weidong Wang,
Michael M. Seidman
Affiliations
Jing Huang
Institute of Chemical Biology and Nanomedicine, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha 410082, China; Corresponding author
Jing Zhang
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Marina A. Bellani
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Durga Pokharel
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Julia Gichimu
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Ryan C. James
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Himabindu Gali
Department of Pharmacology & Experimental Therapeutics and Medicine, Boston University School of Medicine, 72 East Concord St., K-712D, Boston, MA 02118-2526
Chen Ling
Laboratory of Genetics and Genomics, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Zhijiang Yan
Institute of DNA Repair Diseases, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, China
Dongyi Xu
Peking University, Beijing 100871, China
Junjie Chen
Department Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77225-0334, USA
Amom Ruhikanta Meetei
Division of Experimental Hematology and Cancer Biology and Cancer & Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
Lei Li
Department Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 77225-0334, USA
Weidong Wang
Laboratory of Genetics and Genomics, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
Michael M. Seidman
Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA; Corresponding author
Summary: Eukaryotic replisomes are driven by the mini chromosome maintenance (MCM [M]) helicase complex, an offset ring locked around the template for leading strand synthesis by CDC45 (C) and GINS (G) proteins. Although the CDC45 MCM GINS (CMG) structure implies that interstrand crosslinks (ICLs) are absolute blocks to replisomes, recent studies indicate that cells can restart DNA synthesis on the side of the ICL distal to the initial encounter. Here, we report that restart requires ATR and is promoted by FANCD2 and phosphorylated FANCM. Following introduction of genomic ICLs and dependent on ATR and FANCD2 but not on the Fanconi anemia core proteins or FAAP24, FANCM binds the replisome complex, with concomitant release of the GINS proteins. In situ analysis of replisomes proximal to ICLs confirms the ATR-dependent release of GINS proteins while CDC45 is retained on the remodeled replisome. The results demonstrate the plasticity of CMG composition in response to replication stress. : Replication of the mammalian genome is driven by the replisome complex, which unwinds DNA and must overcome many impediments. Zhang et al. find that the encounter of the CMG with a strong block triggers a change in replisome composition that is important for restart of replication past the obstruction. Keywords: replication traverse, interstrand crosslink, ICL, ATR, FANCM, FANCD2, CMG, GINS
